Untangling software delivery with
Team Topologies, flow metrics, and
careful decoupling
Matthew Skelton, Conflux - co-author of Team Topologies
DORA community Talk & Learn | 2023-08-24
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Photo goes here
Matthew Skelton
Founder at Conflux
Co-author of Team Topologies
LinkedIn: linkedin.com/in/matthewskelton
Mastodon: mastodon.social/@matthewskelton
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Team Topologies
Organizing business and
technology teams for fast flow
Matthew Skelton & Manuel Pais
IT Revolution Press, September 2019
Order via stores worldwide:
teamtopologies.com/book
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Team Topologies is the leading
approach to organizing business and
technology teams for fast flow,
providing a practical, step-by‑step,
adaptive model for organizational
design and team interaction.
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Continuously ‘untangle’
business concepts
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Find and adjust team &
system boundaries for flow
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Minimize hand-offs
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Avoid blocking
dependencies
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Move some decision-making
to teams
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Team Topologies exposes any
lack of clarity in purpose,
conflict in priorities, or
misalignment of incentives
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The cost of tangled software
DORA metrics & TT to the rescue!
Real examples of detangling
How to detangle with metrics & TT
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flow
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Use balanced health metrics
(DORA, flow, cost, blockers,
etc.) + TT techniques (TIM,
ISH, UNM) to help find good
boundaries for fast flow by
untangling (decoupling)
separate services
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The cost of tangled software
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If each engineer in the
organization is blocked for
1 hour per working day,
how much does this cost?
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● Fully-loaded cost: €160k per year
● 260 paid days per year
● Total of 400 engineers
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Engineer fully
weighted cost per
year
Engineer cost per day
Hours blocked
per 8-hour day
Days blocked per
260-day year
Cost of blockers
per engineer per
year
Number of
engineers
Total cost of
blockers per year
€160,000.00 €615.38 1 32.5 €20,000.00 400 €8,000,000.00
€8 million per year 💥
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Untangling ≃ Decoupling
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Decoupling: separating
things that do not need
to be together
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Decoupling enables
shorter time-to-value
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Decoupling enables
multiple, independent
flows of change, each
with its own cadence
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Multiple, independent flows
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Decoupling of teams &
technology
vs
Mingling of ideas for
learning
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Decoupling: teams,
software, technology,
deployments, data,
business concepts, ...
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Team autonomy is a
means to an end: rapid
flow of change
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Instead of trying to measure
“team autonomy” directly,
prefer measures like rapid flow,
rapid feedback, minimal
blocking dependencies… 💡
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Sidenote:
Decoupling for reliability
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Decoupling reduces
the number of ways
the software can fail
(failure modes)
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Decoupling helps to
prevent cascading
failure (W → X → Y → Z)
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Decoupling helps
contain the “blast”
when errors occur
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Blast contained!
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DORA metrics &
Team Topologies to the
rescue!
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🔍
Use the 4 Key Metrics
from Accelerate
and add “blocker count”
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Accelerate
Building and Scaling High Performing
Technology Organizations
Nicole Forsgren, Jez Humble, Gene Kim
IT Revolution Press, 2018
Order via stores worldwide:
https://itrevolution.com/book/accelerate/
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4 key metrics: ‘Accelerate’
lead time
deployment frequency
Mean Time To Restore
change fail percentage
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4 key metrics: ‘Accelerate’
lead time
deployment frequency
Mean Time To Restore
change fail percentage
Encourage fast flow
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4 key metrics: ‘Accelerate’
lead time
deployment frequency
Mean Time To Restore
change fail percentage
Encourage operability
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What % of lead time is actual work?
Example: 120 hours / (120+630) x 100 = 16%
Flow Efficiency
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Measuring ‘wait time’ is hard
Count the number of blocking waits as a proxy ✨
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4 key metrics & ‘blocker count’
lead time
deployment frequency
Mean Time To Restore
change fail percentage
‘blocker count’ as a proxy
for flow efficiency
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Use 4 key metrics 📊 +
“blocker count” to assess
and find better service &
team boundaries for flow
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“If we adjusted the
service & team boundary
here, would it improve
the 4 key metrics?” 💓
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“If we adjusted the
service & team boundary
here, reduce the blocker
count?” 📉
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Techniques from the
Team Topologies community
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Independent
Service Heuristics
(ISH)
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“The Independent Service Heuristics (ISH)
are rules-of-thumb (clues) for identifying
candidate value streams and domain
boundaries by seeing if they could be run
as a separate SaaS/cloud product.”
https://teamtopologies.com/ish
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User Needs
Mapping (UNM)
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“User Needs Mapping attempts to capture
the first 4 steps of the Wardley Mapping
process … for identifying potential team
[and service] boundary”
https://teamtopologies.com/unm
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Team Interaction
Modeling (TIM)
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“[Team Interaction Modeling helps] to
describe how to re-organize … teams and
their interactions to achieve better flow and
deliver value faster.”
https://teamtopologies.com/tim
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Real examples of detangling
for fast flow
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Case Study
JP Morgan
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Case Study
“How JP Morgan Applied Team
Topologies to Improve Flow in a Market
Leading Enterprise Platform”
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https://www.youtube.com/
watch?v=y3OL7dv2l48
Fast Flow Conf 💖
https://www.fastflowconf.com/
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Case Study
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Case Study
“60% of dependencies
reduced through better
team design” 💥
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Engineer fully
weighted cost per
year
Engineer cost per day
Hours blocked
per 8-hour day
Days blocked per
260-day year
Cost of blockers
per engineer per
year
Number of
engineers
Total cost of
blockers per year
€160,000.00 €615.38 1 32.5 €20,000.00 400 €8,000,000.00
€8 million per year 💥
Remember this?
[Note: these are not figures from JP Morgan]
Independent Service Heuristics
https://github.com/TeamTopologies/Independent-Service-Heuristics
Rules-of-thumb for identifying
candidate value streams and
domain boundaries by seeing
if they could be run as a
separate SaaS/cloud product.
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2020: New arch
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“Team Topologies ... has given us the
tools we were looking for and have
helped us to build a plan and have
confidence that we know where we’re
going and how to get there.”
Richard Marshall, CTO, Wealth Wizards
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Concepts
● Stream-aligned: build & run
● Boundaries that help flow
● Supporting team types: reduce
cognitive load on Stream teams
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Results
● Clear patterns and language
● Framework for design decisions
● Confidence in scaling approach
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https://medium.com/ww-engineering/to-monolith-or-to-microservice-f8c3f967e63c
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Thanks to:
Richard Marshall
CTO, Wealth Wizards
(to 2021)
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Further details: https://teamtopologies.com/wealthwizards
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Case Study
GOV.UK Home Office
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Case Study
“How the Home Office’s Immigration
Technology department reduced its
cloud costs by 40%”
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https://www.gov.uk/government/case-studies/how-
the-home-offices-immigration-technology-departm
ent-reduced-its-cloud-costs-by-40
Case Study
Making service owners
accountable for the $
spend for their service
helps to clarify service
boundaries 💡
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Use cost metrics as a
“financial scalpel” 🔪 to
split services apart for
fast flow
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How to detangle with metrics
& Team Topologies
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🔍
Track dependencies and
separate as “blocking”
vs “non-blocking”
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⏳ ⏳
Blocking
Non-
Blocking
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🔍
Use tools like
CodeScene to detect
hidden coupling 82
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“Measure how well your organization aligns with your architecture” 💥
https://codescene.com/
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🔍
Use the Team
Dependencies Tracking
tool on GitHub 84
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https://github.com/TeamTopologies/
Team-Dependencies-Tracking
Team Dependencies Tracking
CC BY-SA
Inspired by details
from Spotify
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Use team dependencies
tracking to find and remove
dependencies that hurt
flow
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Team First
Look at your organisation through
the lens of teams, rather than just
the people they work for.
teamform.co
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The cost of tangled software
DORA metrics & TT to the rescue!
Real examples of detangling
How to detangle with metrics & TT
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“You too can save
€8 million per year
by decoupling for
fast flow”
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Use balanced health metrics
(DORA, flow, cost, blockers,
etc.) + TT techniques (ISH,
UNM, TIM) to help find good
boundaries for fast flow by
untangling (decoupling)
separate services
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What’s your perspective?
Which aspects resonate?
Which things feel incorrect?
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expert-led group learning for adopting
fast flow and Team Topologies
confluxhq.com
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thank you
confluxhq.com
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The name “Conflux” and the filled C device are Registered Trademarks ® in multiple jurisdictions.